Introduction: The energy sector poses one of the greatest challenges in most nations as it influences economic growth. Decades of neglect of renewable energy sources has resulted in over dependence on hazardous fossil-fuel. Aims: In this study, we reported the development of high-performance lead-free methyl ammonium germanium halide (CH3NH3GeI3) based Perovskite Photovoltaic cells using computational method. Materials and Methods: The optical property of two dimensional (2D) graphene and mxenes nanocomposites as hole and electron transporters were incorporated to optimize the device performance using SCAP 1D software. The effect of several parameters on the solar cell performance were investigated such as thicknesses of perovskite, hole-transporting materials (HTMs), defect density, hole mobility, and metal electrode work function on the charge collection. Results: Ge-based PSCs with graphene and mxenes (Ti3C2) and TMDCs (NiS2/NiTe2) as alternating HTMs exhibited a remarkable power conversion efficiency (PCE) reaching 21% and a 62.01V; 0.60 mAcm-2; 80.10% as open-circuit voltage, current density and fill factor respectively. Conclusion: Our results advocate for a simple and safe design of HTMs for highly efficient and stable solar cells at low cost.